Internal-combustion engine with self ignition



April 28, 1931. F, L

INTERNAL'COMBUSTION ENGINE WITH SELF IGNITION Filed y 8. 1925 W w i a gwumtoz FRANZ LANG Patented Apr. 28, 1931 UNITED STATES PATENT orFIcE FRANZ LANG, F MUNICH, GERMANY, ASSIGNOR TO ACRO AKTIENGESELLSCHAFT, OF

KUSSNACHT ON THE RIGI, SWITZERLAND INTERNAL-COMBUSTION ENGINE WITH SELF IGNITION Application filed May 8, 1925, Serial No. 28,899, and in Germany July 4, 1924.

This invention relates to'internal combustion engines with self-ignition in which ac cording to one form of the invention the combustion space consists of two chambers, one

6 of which is provided in the piston and the other remaining even at the top dead center position of the piston stroke within the cylinder, that is to say, a chamber is provided in the cylinder beyond or above the ultimate ll position reached by the piston-head in the conhilpression stroke.

otors have been proposed wherein air and fuel are to be separately and successively conducted into a chamber formed in the piston. But since the arrangement thereof is such that they can mix only after reaching said space in the piston, the mixing of the two fluids is unduly retarded and in consequence such mixing is difiicult, so that incomplete combustion occurs.

It has, moreover, been proposed to form a projecting chamber or pocket at the top and outside of the piston, said chamber being adapted to enter a pocket extending from the cylinder-head and to receive the fuel from a fuel injecting nozzle in said cylinder pocket, a vent or vents being arranged at the base of the chamber mounted on the piston. Such an arrangement, however, would not be effective in bringing about a thorough and complete mixture of the fuel with the air in the cylinder head. Incomplete combustion and even failure or difficulty in ignition may result from such an arrangement, as also a gumming up of the fuel injecting valve and injury to the same, since the point of greatest combustion intensity would necessarily be quite close to such part.

An arrangement of parts according to one form of the present invention is distinguished from such devices in various respects, for such arrangement involves the connection of a supplemental chamber within the piston with the remaining space formed in the cylinder by a nozzle-like throttling constriction, the form of the remaining space and the relative arrangement of the fuel and other valves being such that the air-current arising during the compression-stroke will force a stream of air well-mixed with fuel through said throttling constriction into the chamber within the piston. In this manner an extremely intimate mixture of the fuel with air is secured, which greatly facilitates the ignition of the charge and a complete combustion. To achieve particularly good results in this direction the constricted nozzle-like communicating channel should be made relatively short. I also find it advantageous to arrange said channel in line with or co-axial with the fuel injecting nozzle.

Thus the present invention according to the aforesaid one form thereof comprises in combination the said combustion chamber provided in the piston head, the other combustion chamber remaining even at the top center position of the piston stroke within the cylinder, and a nozzle-like-acting arrangement between the said two combustion chambers. This combination serves for the purpose of whirlin the air while throttling the same into the of facilitating the initiation of the self-ignition and of finally extending at the commencement of the working stroke the ignition to the remaining cylinder space.

A particularly effective arrangement embodying the invention according to another form thereof employs the two chambers as before, that is, the chamber provided in the cylinder beyond or above the ultimate position reached by the piston-head in the compression stroke and the supplemental chamber within the piston with the nozzle-like throttling constriction thereto, and also the arrangement of a tapering or funnel-like space or passageway in advance of the nozzlelike constriction and between the same and the fuel injection nozzle or valve and preferably formed as an indentation in the piston head. As hereinafter more fully pointed out, in this other form of, the invention the chamber within the piston functions primarily as an air storage chamber, the air being forced into said chamber and stored therein under compression during the compression stroke of the piston and that air. being discharged therefrom into the cylinder during the working stroke of the piston to supply air needed for combustion.

rst combustion .chamber,

' of the invention, and Figure'2 is a similar illustration showing another form of modification.

Referring to Fig. 1, (1 denotes the piston and b the combustion chamber provided therein; d denotes the other combustion chamber which remains even at the top center position of the piston stroke within the cyllnder; 6 denotes the fuel injection nozzle, f the air supply valve, and g the discharge valve. Now the chamber 6 is contracted at 0, this contraction being so shaped that it forms a nozzle of small diameter and length through which the two combustion chambers b and d communicate with each other. The fuel inabove the nozzle 0 being tapering toward the jecting nozzle or valve 6, it will be noted, is

at a distance from the piston chamber 6, -being separated from the nozzle-like constriction 0 thereof by the width of the chamber d in the cylinder. This nozzle 0 may be a separately manufactured part which is inserted into the piston a.

The operation of the arrangement of parts so described is such that the air entering the cylinder during the working or suction stroke by air-supply valve 7 is during the following compression-stroke of the piston compressed, whereby a strong air-current through the nozzle-like constriction 0 into the pistonchamber b is generated. The fuel issuing from the fuel-injection nozzle e toward the end of the compression stroke, undergoes a preliminary mixing with the airlin chamber d in the cylinder before entering chamber 6 through the constriction c. In through the constriction it is then forced into intimate mixture with the air which has been strongly heated atthe end of the compression stroke, so that the mixture on entering the chamber, will at once ignite, the combustion thus started being then rapidly communicated to every part of the two chambers.

As shown, it is preferred to arrange the fuel injecting nozzle or valve 0 coaxial or in line with the constriction 0, so that a portion of the fuel may at. once be projected into the flowing.

interior of the air current entering the cham-- ber b, thereby augmenting the mixing ac- I tion.

In the modification shown in Fig. 2 the constriction and arrangement of the parts is the same as in the device illustrated in Fig. 1, except that the chamber 12 and its contraction chamber 1) as funnel-shaped and'forming a part of the chamber cl within the cylinder.

In the form shown in Fig. 2, chamber 6 is not a combustion chamber m the sense that much, if any, of the actual burning or combustion of the fuel takes lace within this chamber. Due to the pecu iar arrangement of the parts, the air in the compression space, comprising chambers b and d, compressed during the compression stroke" and most of this air is finally forced and stored, highly compressed, in chamber 6. When the fuel is injected, ignition takes place in chamber (1 and as the iston continues on the working stroke, air rom chamber 1; is discharged to supply the air needed for combustion. In this way combustion continues over a comparatively long part of the working stroke insead of being completed almost immediately after ignition takes place.

I wish it to be understood that instead of only one combustion chamber like I) with a contraction or nozzle like 0 two or more such chambers and nozzles may be provided in one piston. Q

As shown in both figures of the drawings, the piston chamber 1; in the illustrative forms of the invention is pear orbulb-shaped.

I find the pear-shaped form of-t'he pistonchamber which enlarges downward from the constrictionc and is rounded at the bottom particularly advantageous for the proper commingling of the fluids, but of course, my invention generically considered may be embodied in a great variety of forms and is not confined to the one shown.

I claim:

1. An internal combustion-engine with self-ignition comprising a cylinder in combination with a piston, the cylinder bein formed with a combustion chamber beyon the dead-center position of the piston-head, a second chamber being formed within the piston below the piston-head and arranged to communicate with the first chamber, and

a fuel injecting device arranged in the first chamber. j

2. An internal combustion-engine with self-ignition comprising a cylinder in combination with a piston, the cylinder having ar ranged in its interior a combustion-chamber above or beyond the 'dead centerjposition of the piston-head, the piston being formed with another chamber below or behind the piston head and with a constrictednozzle-like communication between the two chambers.

3. An internal. combustion-engine with self-ignition comprising a cylinder in combination with a piston working therein, the

cylinder having in its interior a combustion chamber above or beyond thedead center position of the piston-head, the piston being chamber.

formed with a chamber in its interior and below the piston-head and a nozzle-like communication between the two chambers, a fuel valve being arranged in the first chamber at a distance from the chamber in the piston.

4. In the combination set forth in claim 3, the fuel injecting valve being at the top of the combustion chamber in thecylinder.

5. In the combination set forth in claim 3, the fuel injecting valve being arranged coaxially with the nozzle-like communication.

6. In the combination set forth in claim 3, the pistonvchamber having a pear or bulb shape, its cross-section increasing from the nozzle-like constriction downward.

7. An internal combustion engine with self-i ition, comprising, in combination a charm er provided in the piston and behind the piston head, a combustion chamber remaining even at the top center position of the piston stroke within the cylinder, and a nozzle-like acting entrance to the chamber provided in the piston head.

8. An internal combustion engine with self-ignition, comprising, in combination a chamber provided in the piston and behind the piston head, a combustion chamber remaining even at the top center position of the piston stroke within the cylinder, and a nozzle provided to form the communication between the two chambers.

9. An internal combustion engine with self-ignition, comprising in combination a chamber provided in the piston head,,a combustion chamber remaining even at the to center position of the piston stroke within the cylinder, a nozzle-like acting arrange ment between the said two chambers and a funnel-shaped space within the piston, this space forming a part of the second named 10. In an internal combustion engine, a. cylinder and piston cooperatively formed to provide a compression space consisting of two chambers, one of decreasing dimensions during the inward stroke of the the other formed within the piston walls, below the piston-head, and of fixed dimensions, the two chambers communicating by a throttling orifice.

11. In an internal combustion engine, a cylinder and piston cooperatively formed to provide a compression space consisting of two chambers, one of decreasing dimensions during the inward stroke of the piston and the other formed within the piston walls, below the piston-head, and of fixed dimensions, the two chambers communicating by a throttling orifice, the chamber in the piston storing a combustion-supporting medium during the compression stroke and discharging it during the working stroke.

12. An internal combustion-engine with self-ignition comprising a. cylinder in combination with a piston, the'cylinder being piston and first chamber.

13. An internal combustion-engine with self-ignition comprising a cylinder in combination with a piston, the cylinder having arranged in its interior a combustion-chamber above or beyond the dead-center position of the piston-head, the piston being formed with a second chamber below or behind the combustion-chamber in the cylinder and a,

funnel-shaped space, within the piston and with a nozzle-like constriction, the funnelshaped space communicating with the second chamber through the constriction.

14.. An internal combustion-engine with self-ignition comprising a cylinder in combination with a piston working therein, the cylinder having in its interior a combustion chamber above or beyond the dead-center position of the piston-head, the piston being formed with a chamber in its interior and a funnel-shaped space opening into the first chamber and in communication with the second chamber in the piston through a constriction, in combination with a fuel-injector in the first chamber and facing the funnelshaped space.

15. An internal self-ignition, comprising a cylinder in combination with a piston working therein, the cylinder having in its interior a combustion chamber above or beyond the dead-center osition of the piston head, the piston being formed with a second chamber below or behind the combustion chamber in the cylinder,

combustion-engine with a nozzle like acting constriction between said second chamber storing a combustion-supporting medium during the compression stroke and discharging it during the working stroke.

In testimony whereof I have hereunto affixed my signature.

FRANZ LANG.

In an internal combustion engine with 

